I used to fly a Gumman G164 Agcat. We would sometimes bounce the aircraft off a river. As the wheels struck the water the aircraft would just bounce off, so it was nothing as skilled as these guys. I never put the brakes on, never thought about it. It was a fairly firm feeling I seem to remember, the logic was that water at speed was like hitting a solid surface. Crop spraying was a low down job anyway (in more ways than one) but like skimming a stone, get the angle right and it's OK get it wrong, BIG trouble. I wouldn't do it again, I was young and impressionable in those days, and I wouldn't recommend anyone to try it unless you have a good many hours crop dusting and you know your aircraft very well indeed!